Conventionally, an autonomously moving robot, which senses an obstacle with using a ranging sensor such as a laser-radar or sonar, and performs driving control, is known. In order to drive the autonomously moving robot safely, it is necessary not only to detect the obstacle but also to control it with recognizing what is the detected object. For recognizing the detected object, precise ranging is necessary in whole three-dimensional space. Therefore, it is known to control the driving with obtaining space information from an image provided by a camera. For example, a robot driving with using range information and image information (referring to U.S. Pat. No. 5,525,882) and a technique for measuring a transversal location of an obstacle utilizing a CCD camera and a ultrasonic sensor (referring to Japanese Laid-Open Patent Publication No. 2000-123298) are known.
Furthermore, a robot which moves with recognizing a person by detecting head or front face of the person from images of two cameras is known (referring to Japanese Laid-Open Patent Publication No. 2002-56388). In such literature, a range to the object is calculated from stereographic images. However, when the range to the object is shorter, measurement error becomes larger, so that it is disclosed that the range information by the ranging sensor is used. Still furthermore, a robot, which detects face of a person and calculates a range to the person from images by a stereographic camera and autonomously moves, is known (referring to Japanese Laid-Open Patent Publication No. 2000-326274).